We report the incidence of neonatal seizures in the last 10 years. Between 1981-1990, 28,925 infants were born in the Japanese Red Cross Medical Center. Very low-birth-weight infants (< 1,500 g) were excluded in this study. Seizures were identified in 67 infants (0.23%) during the first 7 days of life. Seizures occurred more frequently in low-birth-weight infants (1,500-2,499 g) than in normal-birth-weight infants (> 2,499 g). Fifty-one infants (0.19%) of 27,276 normal-birth-weight infants and 16 (0.97%) of 1,649 low-birth-weight infants developed seizures. The frequency of seizures was 0.25% during the first 5 years and 0.20% during the second 5 years. In low-birth-weight group, the frequency of seizures decreased form 1.49% to 0.48% during the 5-year periods, and seizures due to post asphyxial hypoxic-ischemic encephalopathy also decreased from 0.14% to 0.06%. The decreased incidence in neonatal seizures during the last 10 years was probably achieved by the progress in intervention of low-birth-weight infants in NICU and by the obstetrical prevention of intrapartum asphyxia.